Do you know that the nutritional profile of bananas changes as they ripen? Have you notice that the riper the banana is, the sweeter it tastes? This is because the enzymes found in bananas is progressively breaking down starch (long polymeric form of sugar that doesn’t taste sweet) into simple sugars (monosaccharides, disaccharides, etc which taste sweet). Since starch has already turned into simple sugar when banana ripens it makes it easier to digest. Although according to studies, the amount of vitamins and minerals lessen as the banana ripens. That is why it’s preferable to store it inside the refrigerator.

Recent study by Japanese researchers has found a very interesting fact about bananas. It turns out that as banana ripens it produces antioxidant and anticancer properties. Full ripe banana with dark patches on yellow skin produces a substance called TNF (Tumor Necrosis Factor) which has the capacity to combat abnormal cells. The study also shows that darker patches it has the higher its anti-cancer quality will be. Moreover, Yellow skin banana with dark spots on it is eight times more effective in enhancing body’s immune system than green skin version.Therefore, it is best to eat banana when it is fully ripe. But if you have type 2 diabetes or you are avoiding a fast increase in your bloodsugar levels, you could consider eating the ripe banana with nut butter – since fat slows down the absorption of sugars into your blood stream. Or you can simply eat the banana while it’s still greenish (level 3 or 4 in the pic)*source:positivemed.com